In Tarrastra, we use the "Fractional Base Bonuses" house rule from the
Unearthed Arcana. This recognizes that all attacks and saves are
actually based on fractional increases per-level, which are rounded
down. When you have a multi-classed character and use the standard
tables from the PHB, you may end up with worse attacks and saves
because you are adding together two rounded-down numbers, rather than
rounding down after adding two fractional numbers.

There are five simple formulae which determine what a particular
character class's attack or save bonus is at a given level. Each class
has one (or two) "good" saves (+2 at level 1 and +12 at level 20), and
two (or one) "poor" saves (+0 at level 1 and +6 at level 20).
Similarly, each class either has a "good" attack bonus (+1 at level 1
and +20 at level 20), an "average" attack bonus (+0 at level 1 and +15
at level 20), or a "poor" attack bonus (+0 at level 1 and +10 at level
20).

Base Attack Bonus (Good)

(Class Level × 1)

Base Attack Bonus (Average)

(Class Level × ¾)

Base Attack Bonus (Poor)

(Class Level × ½)

Base Save Bonus (Good)

2 + (Class Level × ½)

Base Save Bonus (Poor)

(Class Level ÷ 3)

To determine a character's Base Attack Bonus and Base Save Bonuses,
apply the above formulae to each of the character's classes, add up the
results, and round down.

Swashbuckler
Swashbucklers are agile warriors with uncanny battle insight. They
use mobility and precision to harry their foes, outlasting even
those much more powerful than they. Swashbucklers may be honorable
or dastardly; the former may serve as defenders of the weak while
the latter take naturally to life as a brigand. The class is
detailed in Complete Warrior.

Swashbucklers are proficient with basic weapons, light blades, and
any one other weapon group at 1st level. They are proficient with
light armor, but not with shields.

Racial Paragon classes

The racial paragon classes won't simply be available to anyone who wants
to take them: only those characters who accomplish some remarkable
achievement relevant to his race will be eligible to gain levels in a
paragon class.

Paragon Human

Paragon Dwarf

Paragon Elf

Paragon Gnome

Paragon Halfling

Paragon Aasimar

From www.andycollins.net

Paragon Tiefling

Paragon Drow

Just as the drow are a semi-mythical race, stories of mighty exemplars
of that race remain the stuff of legends. But if the race
truly does exist, you can be sure that paragon drow will be out
seeking to subjugate the races of the light.

Prestige classes

Speak to the DM if you are curious about a specific class and don't
have the required source book.

Arcane Archer (Dungeon Master's Guide)

No human sharpshooter can approach the uncanny accuracy and power of an
elven arcane archer.

Requirements to become an Arcane Archer

Race:

Elf.

Base Attack Bonus:

+6.

Feats:

Point Blank Shot, Precise Shot, Weapon Focus(Bows).

Spells:

Ability to cast 1st-level arcane spells.

Archmage (Dungeon Master's Guide)

The most powerful arcane spellcasters are often archmages, who give up
some of their spell capability in order to learn to twist and control
their other spells in powerful ways unavailable to less focused mages.

Requirements to become an Archmage

Skills:

Knowledge (Arcana) 15 ranks, Spellcraft 15 ranks.

Feats:

Skill Focus (Spellcraft), Spell Focus in two schools of magic.

Spells:

Ability to cast 7th-level arcane spells, knowledge of 5th level
or higher spells from at least five schools.

Hierophant (Dungeon Master's Guide)

Powerful divine spellcasters who delay receiving the most powerful
spells can learn to channel and control divine energy in powerful and
unexpected ways.

Requirements to become a Hierophant

Skills:

Knowledge (Religion) 15 ranks.

Feats:

Any metamagic feat.

Spells:

Ability to cast 7th-level divine spells.

Shadow Dancer (Dungeon Master's Guide)

Tricky and deceptive, nimble and adept at weaving through patches
shadow, shadow dancers are mysterious artists of light and darkness.

Requirements to become a Shadow Dancer

Skills:

Move Silently 8 ranks, Hide 10 ranks, Perform (dance) 5 ranks.

Feats:

Combat Reflexes, Dodge, Mobility.

Virtuoso (Song and Silence)

Extroverted, charming, and talented, the virtuoso loves nothing better
than to entertain - and gains some powers while doing so that leave
lesser bards with their mouths agape.

I'm doing this using Prestige Feats, secrets of a bardic college, taught
for free, one per bard level, once the character qualifies and joins the
organization.

NPC Prestige classes

Assassin (Dungeon Master's Guide)

Even the most protected sovereign fears the assassin: the knife in the
dark striking with deadly precision, poisoned, as often as not, the
assailant disappearing into the shadows and escaping with impunity.
What uncanny powers do these fiends wield?

Blackguard (Dungeon Master's Guide)

The quintessential black knight, these vile villains lead armies of
undead and even command demons, while striking down any and all who are
good or holy! Or such is their reputation.

Ur-priest (Book of Vile Darkness)

Only the most experienced clerics speak in horrified whispers of these
vile spell-thieves. How dare they siphon off the divine power
being sent by the deities to their faithful priests? What blasphemy!